1. Field of the Invention
The invention is in the field of imaging device system testing by use of a diffraction limited test image projector.
2. Description of the Prior Art
Test image resolution patterns projected into an imaging device, such as optical or electrooptical systems like the image intensifier system, tend to have chromatic and geometrical abberations which limit the sharpness of the image formed by the lens sytem inside the projector from which the resolution patterns are projected. These abberations tend to enlarge the points of light so that each point merges with the other points close thereto. The resolving power of lens, or lens system, is usually enough that any lack of sharpness of detail is too slight to be observed. However, some imaging devices require a higher quality, i.e. diffraction limited, test image for testing the resolution thereof.
The present test image projector solves the problem of obtaining a diffraction limited test image with broad or narrow spectral band radiation sources in the ultraviolet through the infrared spectrum. Chromatic abberation is eliminated and geometrical abberations are minimized to well below the diffraction limit.